(1) Field of the Invention
The present invention is generally directed toward filtration and particularly to end cap assemblies adapted for interconnecting individual filtration elements within a filter assembly.
(2) Description of the Related Art
End caps or couplers are commonly used to interconnect individual filtration elements in end-to-end relationship within a pressure vessel. In a typical arrangement, end caps are secured to the ends of filtration elements and are adapted to engage with an end cap of an adjacently positioned filtration element. The specific nature of engagement between end caps of adjacent filtration elements may vary depending upon the specific type of element and filter assembly; however, in many applications the engagement involves perfecting a fluid seal and/or mechanical connection between adjacent elements. The end cap is typically circular with an annular surface which is generally co-extensive with the housing of the filtration element. The end cap further includes an outer face adapted to abut against the outer face of an end cap of an adjacently positioned filtration element. The annular surface is often fitted with an elastomeric O-ring, Chevron-type seal or similar means for forming a fluid tight seal between the end cap and the inner surface of a pressure vessel.
U.S. Pat. No. 6,632,356 to Hallan et al. describes such an end cap and filter assembly. Each end cap includes an inner and outer hub connected by a plurality of spokes along with a locking structure provided on the inside of the outer hub. The locking structure specifically includes a plurality of hook or L-shaped projections extending radially inward from the inside of the outer hub of one end cap and a plurality of corresponding receptacles of the outer hub of an adjacent end cap. The end caps of adjacent filtration elements are drawn together and engaged by abutting the annular surfaces of the respective end caps so that the projections of one end cap enter the receptacles of the other and axially rotating one element relative to the other until the projections of one end cap “catch” and are drawn within the corresponding receptacles of the other. Once engaged, relative axial movement between the filtration elements is prevented until the elements are disengaged by counter rotation. Examples of such interlocking end caps are commercially available on selected spiral wound elements sold by The Dow Chemical Company (i.e. elements including iLEC™ interlocking end caps). Additional examples of end caps are provided in: U.S. Pat. Nos. 5,851,267; 6,224,767; 7,063,789 and 7,198,719.